A MULTIDISCIPLINARY MOLECULAR MARKER APPROACHES TO ASSESS THE GENETIC DIVERSITY IN EGYPTIAN DATE PALM

Date palm is one of the most successful fruit crops in tropical and sub-tropical habitats. In the present investigation a multidisciplinary molecular marker approaches including three novel marker types (SCoT, CDDP and ITAP) in addition to (SSR, AFLP and RAPD) were employed to assess the genetic diversity and genetic relationships within and among different Egyptian cultivars. Males and females genotypes representing three or five Egyptian cultivars were assayed using 14 AFLP, 48 SCoT, 14 SSR, 21 CDDP, 18 ITAP and 100 RAPD primers or primer combinations. Amplification products yielded a total no. of bands 591, 484, 83, 192, 204 and 1084, with a percentage of polymorphism 37.4%, 41.3%, 59%, 31.7%, 34% and 24.9%, respectively. The average no. of bands/primer ranged from 5.9 for SSR to 42.2 for AFLP. The cluster analysis of the studied genotypes using these different marker systems revealed five dendrograms exhibited unique topology with some similarities. The generated dendrograms from these marker systems successfully clustered the studied genotypes based on cultivar or gender. The data scored from AFLP, SCoT, SSR, CDDP and ITAP were combined and computed to generate more accurate relationships based on large and versatile genome coverage. The dendrogram based on the combined data exhibited the closest relationships to those illustrated by the AFLP-based dendrogram. On the other hand, the RAPD dendrogram exhibited also a unique topology with some similarities comparing with other marker systems. These results confirmed that different marker systems differ in the mechanism of detecting polymorphism, genome coverage and the ease of application. Therefore, they could complement each other to draw more accurate conclusions.